This invention concerns precursors for biologically active glass in the form of a stable aqueous solution, spheroidal glass particles, supports coated with the precursors, supports coated with the glass, and methods for making the precursor solution, the coated support and the glass particles.
As pointed out by Hench in a review article entitled "Biomaterials" in Science, 208, 826 to 831 (1980), some 2 to 3 million artificial or prosthetic parts are implanted in individuals in the United States each year. These devices, made from a wide variety of materials, are useful, for example, in the eye, the ear, and the nervous system; in the heart, limbs, bladder, and blood vessels; and to repair and replace bones, ligaments, and teeth. In these uses they combat both the degenerative effects of aging and damage resulting from accidents.
A summary of the status of biomaterials and the problems associated with them has been presented by Hall in J. Biomed. Mater. Res. Symposium, No. 2 (Part 1), pages 1 to 4 (1971). The article stresses the importance of the interface between an implant and the body tissue of the host.
U.S. Pat. No. 4,171,544 discloses numerous biologically active glass compositions.
U.S. Pat. No. 4,103,002 discloses a method for coating an alumina, ceramic surface with a biologically active glass. The patent points out that alumina ceramic surfaces are biologically inactive and that bone tissue will not bond to or grow on them.
U.S. Pat. No. 4,159,358 discloses a method for bonding a biologically active glass to a metal surface. In discussing the use of biologically active glasses as biomaterials, the patent states that it is impossible to construct sufficiently strong orthopedic or dental devices from them.
U.S. Pat. No. 4,220,461 discloses deposition of a porous body by the combination of two separate solutions, one a,cidic and one basic, of glass precursors. U.S. Pat. No. 4,135,935 discloses a composite material of biologically active glass and a mineral apatite. GB No. 1,282,307 discloses a method for preparing oxides of two or more elements employing a highly complexing organic substance which is decomposed upon heating.